For background, reference is made to U.S. Pat. No. 5,023,914 disclosing nonminimum phase equalization of a vehicle sound system, and U.S. application Ser. No. 10/290,989, filed on Nov. 8, 2002, disclosing a dual-mode sound system having optimized modes corresponding to different configurational states of an automobile, the entire content of which are incorporated herein by reference.